Portable durometers are known, in which the measurement is effected exerting a thrust with the hands on adzuate projections projecting from the housing of the instrument. Said housing must transmit to the inside member of the instrument a thrust as coaxial as possible relative to the penetrator, in order to avoid wrong measurements.
It happens however that the thrust exerted with the hands is not always perfectly coaxial with the instrument and this is due to various factors, only some of which can be dependent on the operator's attention. The most frequent reason for such an eccentricity of the thrust is due to an untrue abutment of the hands on suitable projections.
Other reasons are the surface inclination of the piece to be measured and the necessity to effect measurements with the apparatus obliquely positioned or horizontally directed. Usually, the operator finds it difficult to realize that the thrust exerted by him is not axial and therefore he cannot readily determine whether the taken measurement is right or not.
The basic aim of the present invention is to avoid or reduce this eccentricity. With the durometer disclosed and illustrated herein, it is possible to apply the thrust easily according to a substantially axial direction.